Developing a tractable shape grammar

Previously, we examined tractable parametric shape grammars and developed a general paradigm for implementing classes of such grammars. A tractable shape grammar has polynomial computing complexity, and is specified in a way that is readily transformable to a computer program. By contrast, traditionally, shape grammars have been typically developed without a computer implementation in mind, either requiring ambiguity to be clarified, or it is hardly possible for the grammar to be implemented by a polynomial algorithm. Each tractable shape grammar is tied to a particular framework, which is backed by a data structure and supports a metalanguage. In this paper we illustrate the development of tractable shape grammars by transforming a shape grammar developed, essentially, in traditional fashion for the Baltimore rowhouse. The development is for a specific application context— to determine the interior layout of a building given its external features—and the process serves as a general strategy for developing tractable shape grammars.